In the past, it has been well known to display engineers that LCDs work best with light passing therethrough at normal or near normal angles of incidence. Light passing through LCD cells can suffer a change in the state of polarization which are a function of wavelength and make objectional changes in the color and contrast of the display when viewed off axis. One solution to this problem is to collimate the light entering the LCD cell from its back light and to let it pass through the cell, at or near normal incidence and then, decollimate or diffuse the light after it has passed through the cell so that, it can be viewed from all directions without objectional color or contrast changes.
While displays which utilize such a collimation of light have been used in the past, they do suffer from several serious drawbacks. One problem is the inclusion of bulky optics introduced between the LCD cell and the back light. These optics have been typically lenses or reflectors and have objectional drawbacks such as size and cost.
Consequently, there exists a need for improvement in avionics LCDs which have enhanced viewability from off axis viewing angles.